Gear



March 18, 1930. H. u. MITCHELL GEAR Filed May 5, 1928 Inventor VEQVZ/fcfia Patented Mar. 18, 1930 UNITED STATES HAROLD U. MITCHELL, OFMEDFOBD, OREGON GEAR Application filed May 5, 1928.

The present invention relates to improvements in gears and has for itsprime object to provide a gear with means for automatically compensatingfor back lash and the like due to wear.

A still further very important object of the invention resides in animproved gear of this nature which is exceedingly simple in itsconstruction, inexpensive to manufacture,

in strong and durable, and thoroughly efficient and reliable in use.

\Vith the above and numerous other objects in View as will appear as thedescription proceeds, the invention resides in cer- 15 tain novelfeatures of construction, and in the combination and arrangement ofparts as will be hereinafter more fully described and claimed.

In the drawings: I

Figure 1 is a side elevation of a gear embodying the features of myinvention,

Figure 2 is av sect-ion therethrough taken substantially on the line 2-2of Figure 1, and

Figure 8 is a detail section therethrough taken substatnially on theline 33 of Figure 1.

Referring to the drawing in detail it will be seen that the numeral 5denotes the gear 30 with peripheral teeth 6 and the center of this gearis thickened to provide an annular shoulder 7 about which is adjustablea ring 8 with peripheral teeth 9. Bolts 10 or equivalent fasteningelements are disposed through 35 the thicker portion of the gear 5 andhave washers 11 thereon to engage over the ring 8 and hold the same inplace but allow the ring to revolve so as to change the location of theteeth 9 in respect to the teeth 6 for compensating for any wear in theteeth 6 thereby eliminating back lash and the like.

I have devised means for automatically adjusting the ring in respect tothe gear and in the present embodiment this means in eludes theprovision of an opening 12 through the ring 8, a pin 14 projectinglaterally from the gear 5 into the opening 12 and a wedge 15 movablealong one wall of the opening and en- 'gaging against the pin 14: andbeing pressed inwardly by a spring 16. A cover plate 17 is Serial no.275,442.

anchored as at 18 to the ring 8 and extends over the opening 12. It willthus be seen that if wear takes place in the teeth 6 and 9 the same willbe compensated by the circumferential movement of the ring 8 therebyshifting the teeth 9 in respect to the teeth 6 and positivelyeliminating back lash.

' The ring is locked after having been moved because of the relationshipbetween the pin and the wedge. It is thought that the construction,operation and advantages of the invention will now be quite apparent tothose skilled in this art without a more detailed description thereof.

The present embodiment of the invention has been disclosed in detailmerely by way of example since in actual practice it obtains thefeatures of advantage enumerated as desirable in the statement of theinvention and the above description. It is apparent, however, thatchanges in the details of construction, and in the combination andarrangement of parts may be resorted to without departing from thespirit or scope of the invention, as hereinafter claimed or sacrificingany of its advantages.

Having thus described my invention, what I claim as new is:

In combination, a gear having peripheral teeth and provided with anannular concentric shoulder, a ring movable about the shoulder andhaving peripheral teeth associated with the first mentioned teeth, saidring being provided with an opening, a pin on the gear extending in theopening, a wedge between the pin and one wall of the opening, and aspring impinging against the wedge.

In testimony whereof I a'liix my signature.

HAROLD U. MITCHELL.

